This additional introduction of pollutants could either endanger the indoor environment or create a sufficient parasitic energy demand to counteract any benefit of the technology. Ventilation can often be provided directly using renewable technologies, either passively or actively, but additional ventilation, even when provided passively, can increase the thermal load of the building. This report reviews the subject of indoor air quality with particular emphasis on the role and http://parquet.netau.net impact of renewables. The complexity of modern buildings presents significant unmet challenges to designers, operators and investigators. Problems other than air quality can cause or exacerbate the symptoms of Sick Building Syndrome. Psychological and social as well as physical and biological factors interact to create occupant physiological and health responses to building environments.